Sandpoint climate

Sandpoint Frost Dates and Growing Season

NOAA 1991-2020 normals for Sandpoint Exp Stn, 2 km from Sandpoint, elevation 2126 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Sandpoint Exp Stn. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around May 8 and the first fall freeze around September 28, a growing season of about 141 days.

Median at 36°F
last May 28, first September 13
Median at 32°F
last May 8, first September 28
Median at 28°F
last April 21, first October 10

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FJun 17Jun 10Jun 4May 31May 28May 25May 21May 17May 11
32°FMay 25May 20May 15May 12May 8May 4May 1Apr 28Apr 23
28°FMay 7May 1Apr 28Apr 24Apr 21Apr 16Apr 12Apr 6Mar 31
24°FApr 20Apr 11Apr 6Mar 31Mar 29Mar 25Mar 22Mar 17Mar 11
20°FMar 30Mar 23Mar 19Mar 14Mar 11Mar 8Mar 4Mar 1Feb 23
16°FMar 17Mar 11Mar 7Mar 4Mar 1Feb 27Feb 21Feb 15Feb 4

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FSep 1Sep 4Sep 7Sep 10Sep 13Sep 16Sep 20Sep 23Sep 27
32°FSep 11Sep 18Sep 22Sep 25Sep 28Sep 30Oct 2Oct 5Oct 11
28°FSep 25Oct 1Oct 4Oct 6Oct 10Oct 13Oct 17Oct 22Oct 29
24°FOct 5Oct 12Oct 17Oct 21Oct 25Oct 30Nov 2Nov 9Nov 16
20°FOct 20Oct 26Nov 1Nov 5Nov 10Nov 15Nov 21Nov 26Dec 4
16°FOct 31Nov 8Nov 14Nov 22Nov 27Dec 1Dec 5Dec 10Dec 19

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F1311241181131091051009384
32°F161154149145141137133126118
28°F197188182177172168162155147
24°F237227221215210204199192182
20°F272263256250244239233225214
16°F303292283277271266260252243

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
7,087
Cooling degree days, base 65°F
233
Growing degree days, base 40°F
3,585
Growing degree days, base 45°F
2,578
Growing degree days, base 50°F
1,745
Growing degree days, base 55°F
1,072
Growing degree days, base 60°F
563

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,13900
February95100
March85301
April599024
May3514160
June18625294
July56108518
August5986492
September24810226
October614029
November89001
December1,14200

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 2 km from Sandpoint. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00108137 (Sandpoint Exp Stn). Public domain.